This invention relates to buildings, building components, building subassemblies, and building assemblies, and to methods of constructing buildings and building components. This invention relates specifically to components, subassemblies, and to assemblies, as parts of the building, to methods of making and using building components in the process of constructing buildings, and to the issue of worker safety during the construction of buildings.
From time to time, injuries occur during construction of buildings, including to workers who fall from elevated heights. The focus of this invention is to enable a building contractor to reduce, desirably to eliminate, the number of incidents of worker injuries resulting from workers falling from elevated heights while working on construction of the building.
When a worker falls, and travels some distance before impacting a support, the force of the impact has two parts. The first part impact force is the static force of gravity on the person's body. The second part of the impact force is the kinetic energy related to the velocity of the moving body.
In order for a fall protection system to work, such system must be able to arrest the person's fall, and be able to subsequently sustain support of the person's weight until the person can be retrieved, removed from the fall protection system. In most falls, the controlling requirement is that the system be able to arrest and dissipate the kinetic energy associated with the falling body without the body passing through the fall protection system.
Governmental safety organizations, for example the Occupational Safety and Health Administration (OSHA) in the US, have promulgated required safety standards, and safety practices to generally provide safety systems which capture and support workers who are working at substantial heights above supporting surfaces, to protect such workers, namely to stop a fall, and to support such workers if/when such workers fall. But it is up to the industry to create fall protection systems which meet the required, standards.
With pre-engineered building systems now being the predominant method of non-residential low rise construction for buildings, existing fall protection standards have substantial impact on the contractors involved.
One way a worker can be protected, according to the standards, is for the worker to wear a safety harness which is tied, by a strap, to the building structure such that the harness/strap combination stops any fall which the worker experiences before the worker encounters an underlying surface such as a floor or the ground. Use of such safety harness is known as “tying off”. But tying the harness to the building limits the workers range of movement. Thus tie-off harnesses are not viewed favorably in the industry.
Another way the workers, can be protected is for the building contractor to erect heavy and expensive safety nets in order to provide leading edge protection against falls. Cost and maintenance of such nets and associated equipment, the expense of erecting and dismantling such nets and associated equipment, and moving and storing such nets and equipment, can be a substantial increment in the per square foot cost of especially the roof insulation system being installed.
With the anticipation of expanded enforcement efforts by OSHA, building erectors have increased incentive to find ways to meet the existing fall protection requirements.
Another acceptable fall protection system is a passive system wherein a fabric, such as a solid sheet, a woven sheet, or a net-like material, is suspended at or below the work area, optionally supported by a grid of crossing support bands, with the system far enough above any underlying supporting surface to catch and support a worker who falls, thereby to act as a passive fall-protection system.
Under Regulations Section 1926.502(c)(4), OSHA has defined a drop test procedure whereby a such passive fall protection system can be tested. According to the test procedure, a 400 pound weight is dropped onto the fall protection system under stated conditions to determine whether a given system meets the required safety standards. For purposes of complying with government regulations, any system used as a fall protection system need only meet the OSHA-mandated standards related to dropping such 400 pound weight. Of course, the real humanitarian objective is to prevent worker injuries if/when a worker falls from an elevated work location. Thus, any fall protection system which is effective to catch and safely hold a falling worker has operational value, even if such system does not meet OSHA standards.
According to one aspect of the prior art, currently in use in the metal building industry, and intended to meet government fall protection standards, a purported fall protection system uses crossing longitudinal and lateral metal bands extending under the eave, under the ridge, and under the intermediate purlins, and a fabric is installed above the bands and under the purlins, extending across the entirety of a respective bay of the building being constructed, thereby providing a suspended fabric intended to catch and support a falling worker in that bay. Insulation is ultimately installed on the top surface of the fabric whereby the fabric ultimately functions as the vapor barrier portion of the building ceiling insulation system in the finished building.
Testing has shown that currently-available such systems meet the government-mandated drop test standard at certain locations in the bay of a metal building under construction, while failing such drop test at other locations. Typically, such systems fail the drop test adjacent an edge of the bay, where any worker accidental fall is most likely to occur.
Thus, the user cannot be assured that a falling worker will be caught and supported at whatever location he/she falls from at the elevated work location. Such failure can result in worker injury, along with the numerous detrimental results of such injury, as well as resulting government citations associated with the resulting injury, and associated monetary fines and/or assessments, civil lawsuits, and the like.
Failures of the drop test are typically associated with breakage of the bands and penetration of the fabric. Even when the fabric successfully catches and holds the dropped bay, there are significant tears in the fabric at the screws which extend through the fabric at those locations closest to the point of impact. Limited fabric tear at the screws, and breakage of the bands, are acceptable so long as the bag does not pass through the fabric. Both band breakage and limited fabric tears are common even in instances when the “system” passes the test.
The problem plaguing the industry is to design a fall protection system which passes the test irrespective of where, in the bay, is the point of impact of the dropped bag. Testing has shown that the areas of the bay where a passive such fall protection system is most susceptible to failing the drop test are the areas adjacent the rafters.
Accordingly, there is a need for a novel passive fall protection system for use during construction of metal buildings which effectively catches and supports a falling worker working at an elevated height, and which system meets all governmental safety standards at all areas of the bay, including adjacent the rafters.
There is also a need to provide a portion of a building insulation system which functions to provide effective fall protection during construction of the building, while meeting the existing governmental fall protection requirements.
There is further a need for methods of mounting fall protection systems to building structural members during construction of metal buildings, fall protection systems which effectively catch and support a falling worker working at an elevated height, and which systems meet all governmental safety standards.
There is yet further a need to provide novel band and fabric products to passive fall protection systems, which enhance worker safety and efficiency.
Still further, there is a need to provide novel methods of making and using components of the fall protection system so as to enhance worker safety and efficiency.
These and other needs are alleviated, or at least attenuated, or partially or completely satisfied, by novel products, systems, and methods of the invention.